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RUN light ON (No TIMER light)

RUN light ON (No TIMER light) - Cooling high pressure protection

MHI · Air Conditioning

What does RUN light ON (No TIMER light) mean?

The system has activated a protection mechanism due to excessively high pressure in the cooling circuit. This can indicate an overcharge of refrigerant or an issue with the outdoor unit.

Common Causes

  • Overcharge of refrigerant.
  • Short circuit of the outdoor unit.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the air conditioner at the main circuit breaker and wait at least 30 minutes to allow pressures to stabilize.

  2. 2

    Ensure the outdoor unit is clean and free of obstructions, allowing for proper airflow and heat dissipation.

  3. 3

    If the protection persists, contact a qualified service technician, as issues with refrigerant charge or electrical short circuits require professional attention.

Browse all codes in this manual (124)
Verified technical data. Last updated: April 2026

Related Faults

00Outdoor Board LED only green lights up after startup - No outdoor unit of address 0 / Remote controller transmission wire open1OPERATION INDICATOR lamp blinks 1 time (Pattern A) - Indoor/outdoor unit communication error (Transmitting error - Outdoor unit)14OPERATION INDICATOR lamp blinks 14 times (Pattern A) - Other errors
Source: MHI Air Conditioning
Open Manual (Page 38)Search more codes in this manual